5. Local control of exposure. As stated earlier, projection printing
permits a great deal of print control.
a. In some instances, the range of brightness values in a photo may be
too great to be reproduced in a straight print. However, adequate
compensation can usually be made by shading the area which prints too dark.
For example, detail in shadow areas can be preserved by dodging (holding
back the light) during part of the exposure. Dodging can usually be
accomplished more easily and accurately in projection printing than in
Figure 29. Using the hands as a dodging device
b. Since the dodging material is held and manipulated in the beam of
light between the lens and paper, its location and coverage can be seen and
controlled during the printing exposure. As shown in Figure 29, the
dodging device may be nothing more than your hands. It is surprising how
many shapes you can form with your hands.